Google co-founder Sergey Brin is known as the leader of Google X, and being on the Google X team is one of the most coveted roles at Google, and in the Valley at large. The labs are located at Google’s Mountain View, headquarters.

Apart from Brin, the team works under leader Eric “Astro” Teller. Astro was also the co-founder and CEO of BodyMedia, a wearable body monitoring company that was sold to Jawbone in 2013. When not building wild new tech at Google, he’s the co-founder and a director at investment firm Cerebellum Capital.

Another Google X leader is Rich DeVaul, captain of two teams known as the “Rapid Evaluation Team” and the “Design Kitchen.” These are two small groups who prototype, build, and test ideas, searching for the Next Big Thing.

For instance, DeVaul leads something called Project Loon, which delivers Internet connection by means of a high-altitude balloon. It hopes to one day bring Internet to the 4.8 billion people who live in far out places without Internet access.

Google just obtained some government-managed radio waves (known as licensed radio spectrum) and is said to be testing the balloons in secret trials in Nevada, reports PC World.

The day Fast Company was there, the Design Kitchen built a prototype for a “thermo-acoustic engine” which converts heat into mechanical operations. It’s a hard engineering problem that, if solved, could have a huge impact for green energy.

Ultimately Google X wants to invent new technologies and they don’t mind if their prototypes fail, Teller says. Unlike other R&D labs, they are working on what’s called “moonshots,” tech experiments that beyond longshots. They aren’t under a lot of pressure to create new commercial products, but some of their creations will likely be big hits, like Google Glass.